Acceptance Testing: Datadog HTTP Log Export API is missing fields/tags

The logs collected in Datadog using the new [Datadog HTTP Log Export API](https://docs.datadoghq.com/api/latest/logs/) for Self-Hosted are missing critical fields and tags to help users identify, filter, build, and correlate dashboards.

This issue tracks

1. Providing a default/static fields and tags for critical fields:

- SOURCE: cockroachdb
- HOST: hostname of the node

2. Allow generic/custom tagging during CRDB deployment in the YAML file, example tags and values:
```yaml
tags:
env:
service:
team:
chargeback:
apps:
```

Custom tagging will override any default fields (SOURCE and HOST).

[Agent log (with expected tags/fields)
](https://app.datadoghq.com/logs?query=&cols=host%2Cservice&event=AgAAAYkxB1BOKP8_ywAAAAAAAAAYAAAAAEFZa3hCMXZyQUFBSUwyZFhoNXlnWGdBQgAAACQAAAAAMDE4OTMxMDctNjdkMC00ZjQ4LThiYzAtODY2NWM4ZmU1OTg3&index=%2A&messageDisplay=inline&stream_sort=desc&viz=stream&from_ts=1688740079295&to_ts=1688743679295&live=true)

[HTTP Export API log
](https://app.datadoghq.com/logs?query=-source%3Acockroachdb&cols=host%2Cservice&event=AgAAAYkHS0qGipwH9QAAAAAAAAAYAAAAAEFZa0hTMHFHQUFDRllmY2liaDlQN0FBQQAAACQAAAAAMDE4OTA3ZDUtM2UzOS00NGRjLWE2NWEtN2E2MGY3YzIyNjQ0&index=%2A&messageDisplay=inline&stream_sort=desc&viz=stream&from_ts=1686151005157&to_ts=1688743005157&live=true)

Related issue:

- https://github.com/cockroachdb/cockroach/issues/103477

Jira issue: CRDB-29555

Epic CRDB-32142